Interacting holes in a gated WSe$_2$ quantum channel: valley correlations and zigzag Wigner crystal

TL;DR

This paper develops a theoretical framework for interacting holes in a gated WSe$_2$ quantum channel, revealing valley polarization, antiferromagnetic phases, and zigzag Wigner crystal formation influenced by interactions, magnetic fields, and spin-orbit coupling.

Contribution

It introduces a comprehensive microscopic model and analysis of valley and charge phases in WSe$_2$ quantum channels, highlighting novel symmetry-breaking and crystal phases.

Findings

Valley-polarized states due to strong interactions.

Valley-antiferromagnetic phase at weaker interactions.

Prediction of zigzag Wigner crystal formation at low densities.

Abstract

We present a theory of interacting valence holes in a gate-defined one-dimensional quantum channel in a single layer of a transition metal dichalcogenide material WSe$_2$. Based on a microscopic atomistic tight-binding model and Hartree-Fock and exact configuration-interaction tools we demonstrate the possibility of symmetry-broken valley polarized states for strongly interacting holes. The interplay between interactions, perpendicular magnetic field, and the lateral confinement asymmetry together with the strong Rashba spin-orbit coupling present in WSe$_2$ material is analyzed, and its impact on valley polarization is discussed. For weaker interactions, an investigation of the pair correlation function reveals a valley-antiferromagnetic phase. For low hole densities, a formation of a zigzag Wigner crystal phase is predicted. The impact of various hole liquid phases on transport in a high mobility quasi-one dimensional channel is discussed.